JP2001174888A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera preventing a battery from being deteriorated due to heat generation, preventing it from being decreased in the available number of times for recharging, and permitting to use the rechargeable battery for a long time. SOLUTION: In this camera, an output current of a solar battery 2 is charged in a secondary battery 25, and the camera is sequence-controlled by a CPU 11 using the secondary battery 25 as an energy source. Then, the charged voltage of the secondary battery is monitored by the above CPU 11 and a recharged amount to the above solar battery is also monitored. The CPU 11 controls the consumption of current based on the recharged voltage to the secondary battery 25 and the recharged amount to the above solar battery 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera that can use a rechargeable secondary battery, and more particularly to a camera that can prevent a secondary battery from being overcharged by a solar cell.

[0002]

2. Description of the Related Art In recent years, various cameras using rechargeable batteries have been developed. For example, a camera is known in which a secondary battery is charged by a solar battery or the like, and the camera can be driven by the energy.

For example, Japanese Patent Application Laid-Open No. 9-36409 discloses a technique in which a charger is mounted on a camera case, and a battery built in the camera is charged by setting the camera in the charger.

[0004] Japanese Patent Application Laid-Open No. 6-163965 discloses a technique for attaching a solar cell to a camera adapter.

As described above, cameras capable of charging energy by various methods are widely known.

[0006]

By the way, a rechargeable battery is liable to generate heat if used improperly, and is liable to be affected by the life of the charge / discharge cycle of the battery. Under such an influence, the battery is deteriorated, which causes problems such as a reduction in the number of films and frames to be photographed and a reduction in usable time.

[0007] However, Japanese Patent Application Laid-Open No. 9-36409 describes the above.
In Japanese Patent Application Laid-Open No. H06-163965, there is no description about measures against such heat generation and the life of the number of times of charge / discharge. For this reason, the deterioration of the battery described above causes a reduction in the number of films or frames that can be photographed, a reduction in usable time, and the like.

Accordingly, the present invention has been made in view of the above-mentioned problems, and it is possible to prevent deterioration of a battery due to heat generation, to prevent a reduction in the number of times that a battery can be used, and to allow a rechargeable battery to be used for a long time. The purpose is to provide a camera.

[0009]

That is, the present invention provides a solar cell, a secondary battery for storing the output current of the solar cell, an electronic circuit for controlling the sequence of a camera using the secondary battery as an energy source, Wherein the electronic circuit comprises: first monitor means for monitoring a charge voltage of the secondary battery; second monitor means for monitoring a charge amount of the solar battery; And control means for controlling the current consumption of the electronic circuit based on the charging voltage to the secondary battery and the amount of charge to the solar cell obtained by the second monitoring means.

The present invention also provides a camera comprising a solar cell, a secondary battery for storing the output current of the solar cell, and an electronic circuit for controlling the sequence of the camera using the secondary battery as an energy source. The electronic circuit includes a temperature detecting unit that detects a temperature inside the camera, and a prohibiting unit that prohibits a charging operation of the secondary battery according to an output result of the temperature detecting unit. .

Further, in the present invention, in a camera using a secondary battery having two charging methods, a judging means for judging that the charging by one charging method has been completed, and a battery consuming method after judging the charging completion. And a permitting means for permitting charging by the other charging method according to the result of the determination by the determining means.

In the camera of the present invention, the output current of the solar cell is stored in the secondary battery, and the sequence control of the camera is performed by an electronic circuit using the secondary battery as an energy source. Then, in the electronic circuit, the charging voltage of the secondary battery is monitored by the first monitoring means, and the charge amount of the solar battery is monitored by the second monitoring means. The control means controls the current consumption of the electronic circuit based on the charging voltage to the secondary battery and the amount of charge to the solar cell obtained by the first and second monitoring means.

In the camera of the present invention, the output current of the solar cell is stored in the secondary battery, and the sequence control of the camera is performed by an electronic circuit using the secondary battery as an energy source. Then, in the electronic circuit, the temperature inside the camera is detected by the temperature detecting means, and the charging operation of the secondary battery is prohibited by the prohibiting means according to the output result of the temperature detecting means.

Further, in the camera of the present invention, a secondary battery having two charging systems is used,
The judging means judges that the charging by one of the charging methods is completed, and the judging means judges the battery consumption after the judgment of the completion of the charging. Then, according to the determination result of the determination means, charging by the other charging method is permitted by the permission means.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view showing the appearance of the camera and the charger of the camera according to the first embodiment of the present invention.

In FIG. 2, a panel of a solar cell 2, a slidable barrier 3 for protecting a photographing lens, a strobe light emitting section 4, and a PCV for warning are provided on the front of the body of the camera 1.
5 and the like are arranged. A display unit 6 is provided on the upper surface of the main body of the camera 1 so that patterns and characters can be displayed on an LCD or the like.

Further, a secondary battery which can be AC-charged from an AC power source by a charger 8 through an AC cord 9 is built in the camera body. In addition, the secondary battery has a specification that can convert the energy of light received by the solar cell 2 into electric energy and charge the electric energy.

In the camera having such a configuration, both the AC charging and the sunlight charging are performed, so that care must be taken in managing the charging method.

FIG. 3A is a graph showing charge control of a lithium ion battery.

When the voltage is low, the charging current may be a large value. However, when the voltage rises, it is necessary to flow the battery with a small current due to physical properties. Failure to comply with such a method will result in reduced battery life. Further, even if the battery is charged more than necessary, the battery is deteriorated due to overcharging. This may lead to the problem that no matter how much the camera 1 is set on the charger 8, the camera 1 cannot be charged, or the number of frames that can be shot is reduced even if the camera 1 is charged.

The charging operation of the battery is preferably performed within a predetermined temperature range, as shown in FIG.
For example, charging at 0 ° C. or lower and 40 ° C. or higher leads to the above-described deterioration of the life.

For this reason, in the present invention, a battery fully charged by AC charging is prevented from being overcharged by being further solar-charged, or from being degraded by being charged in an inappropriate temperature range. The circuit configuration shown in FIG. 1 is used to improve the life of the battery.

In FIG. 1, a CPU 11 is an arithmetic and control means constituted by a one-chip microcomputer or the like. The CPU 11 includes a DC / DC converter 12,
The solar cell 2 is connected via the diode 13, and the A / D converter 14, the reset IC 15, the display circuit 16, the warning unit 17, the strobe 18, the temperature sensor 19, and the EEPROM 20 are connected. CPU1
A transistor 24 for switching the charge on / off of the solar cell 2 is connected to 1 via a resistor 23. Incidentally, 25
Is a secondary battery that can be charged from the solar cell 2 and the AC power supply described above.

When the CPU 11 is charged to a predetermined voltage by the action of the reset IC 15, the built-in RO
The operation is started by an M (not shown) program.

The charging current I _P from the solar cell 2 is detected from the voltage across the diode 13. As for the diode characteristics, as the current flows, the voltage at both ends increases.However, since the detailed value differs for each product due to manufacturing variations, the characteristics are stored in an electrically writable memory in the camera manufacturing process. Remember.

When the DC / DC converter 12 is turned on, the power supply voltage of the CPU 11 can be set higher than the battery voltage level. Since the A / D converter 14 is also driven by a high voltage, the voltage between both ends of the diode 13 is also A / D converted, and
Can be entered.

Further, the CPU 11 executes the above-described strobe 1
In addition to controlling the photographing sequence of the camera 8 and the like, the display circuit 16 and the warning unit 17 of the camera are controlled to convey information to the user. In addition, the camera operating environment temperature (temperature at the time of charging) can be monitored from the output of the temperature sensor 19.

On the other hand, an AC / AC converter 30 is built in the charger 8, and a primary coil 31 is connected to the AC / AC converter 30. A stabilizing capacitor 34 of an AC power supply unit 40 is connected to a secondary coil 32 facing the primary coil 31 via a rectifier circuit 33.

The AC power supply 40 includes a diode 36
And the current I _AC of the current source 38 by each of the current sources 41a, 41b,
A circuit formed by the current 41c is provided. Also,
42 is a current mirror circuit.

The current sources 41a, 41b and 41c correspond to the three-stage current shown in FIG. And
When the emitters of the PNP transistors of the current sources 41a, 41b, and 41c are selectively opened through the transistor 43 by the open drain port of the CPU 11, the current supply is started. The secondary battery 25 is charged by these charging currents, and the current from the solar cell 2 also flows into the secondary battery 25. However, when the transistor 24 is turned on under the control of the CPU 11, charging by the solar cell 2 is prohibited.

A through the AC / AC converter 31
When the energy of the C commercial power supply is further increased in frequency and supplied to the primary side coil 31, a current is generated in the secondary side coil 32. The generated current is rectified by the rectifier circuit 33 and the circuit of the AC power supply unit 40 stabilized by the stabilizing capacitor 34 is activated. The transfer of the magnetic energy enables non-contact charging of the charger.

[0033] In such a configuration, so as not to charge the output current I _P from the solar battery 2 to the secondary battery 25, the current consumption I _F circuit of the DC / DC converter 12 after I _P It should be almost the same. At this time, I _F =
It becomes 0. As a situation where the user does not want to charge the battery, there is a case where the secondary battery 25 is already fully charged by AC charging, or a case where the battery 25 is out of the recommended temperature range.

[0034] To increase or decrease the current consumption I _F may be driven display circuit 16 and the warning unit 17. For example, as shown in FIG. 4, when a warning is issued from the camera 1, the user 10 can prevent the overcharging by deflecting the camera 1 from the sunshine or putting it in a bag. .

Further, if the display is changed one after another and performed in an animation style, the current consumption is increased and the user can enjoy the specification.

More specifically, under the control of the CPU 11 based on the flowchart shown in FIG.
It is possible to control the charging by the solar cell, prevent overcharging, and extend the battery life.

First, in step S1, the state of a release switch (SW) not shown is determined. Here, if the release switch is pressed, step S
Go to step 15 and enter the shooting-kens. On the other hand, if there is no release operation, the process proceeds to step S2, and as described above, the DC / DC converter 12 is started, the voltage level of the A / D converter 14 is increased, and the diode 1
The voltage between both ends is obtained, and this difference is referred to as the storage result of the EEPROM 20, and the output current _IP is monitored.

Next, in step S3, it is determined whether or not charging by the solar cell 2 is performed. here,
I _P is not "0", when was charged by the solar cell 2, the process proceeds to step S4, DC / DC converter 12 is turned on the battery voltage V _B is determined. Then, in step S5, a predetermined level V _B0 of charge control in accordance with its level the battery voltage V _B is performed it is compared.

Here, if the battery voltage V _B exceeds the predetermined level V _B0 , the flow shifts to step S6, where the current is canceled according to the charging current, and the current is consumed so that overcharging is not performed. That is, the above _IP and the predetermined level _IP1
Is compared with As a result, the current _IP becomes equal to the predetermined current IP.
If it is smaller than _{P1, the process} proceeds to step S7, where the display switching cycle is set to 0.5 sec, the consumption is reduced and charging is not performed, and the reduction of battery energy due to consumption is also prevented. Thereafter, the process proceeds to step S1.

On the other hand, if the current I _P in the step S6 is larger than the predetermined current I _P1, the display shifts to step S13 is switched to 0.1sec every further step S
A warning is also given at 14. Thereafter, the process proceeds to step S1.

If the battery voltage is low in step S5, the process shifts to step S10 to determine whether the temperature range is within a predetermined range. here,
If the temperature range is beyond the predetermined range, step S1
Then, the transistor 24 is turned on to prohibit charging. Thereafter, the process proceeds to step S1.

On the other hand, if it is determined in step S10 that the temperature is within the above-mentioned temperature range, the process proceeds to step S12, in which the charging display is performed with a small current consumption, and the charging is performed with the remaining current. Thereafter, the process proceeds to step S1.

If charging by the solar cell 2 has not been performed, the process proceeds from step S3 to step S8, and it is determined whether or not AC charging has been performed. Where AC
If charging has not been performed, the process proceeds to step S1. On the other hand, if the AC charging is performed, the process proceeds to step S9, and the transistors of the current sources 41a to 41c are turned on / off according to the charging voltage and the AC charging is performed according to the relationship illustrated in FIG. . This is because the current mirror circuit 42 is turned on and the transistor 43 is turned on.
It is determined by monitoring by U11. This CPU port is pulled up inside the CPU 11. Thereafter, the process proceeds to step S1.

If it is determined in step S1 that the release switch (not shown) has been turned on, the process proceeds to steps S15 to S15.
The flow shifts to 18, where a shooting sequence is performed. That is, the distance measurement and the photometry operation are performed in step S15, and then the focusing is performed in step S16. Then, when the shutter is controlled in step S17 and predetermined photographing is performed, the film is wound in step S18. Thereafter, the process proceeds to step S1.

As described above, according to the first embodiment, overcharging can be prevented and battery life can be prolonged by AC charging or solar cell charging by the flowchart shown in FIG. it can.

Further, after the battery is fully charged by AC charging according to the flow chart shown in FIG. 6, it is possible to prevent the battery from being overcharged by the solar battery and causing the battery from deteriorating.

As shown in FIG. 7, the amount of energy charged to the battery may not be proportional to the voltage, so that it is difficult to finely control the solar charging according to the result of the battery voltage determination.

Therefore, in the second embodiment, fine charging current control is performed at the time of AC charging to prohibit only solar charging after full charging, thereby simply extending the battery life.

Hereinafter, the operation of the second embodiment of the present invention will be described with reference to the flowchart of FIG.
The components of the second embodiment are the same as those of the above-described first embodiment, and a description thereof will not be repeated.

When charging with a solar cell, current cannot be supplied as much as AC charging (1/10 or less of AC charging), so that overcharging does not occur frequently in practical use.

Therefore, first, in step S21, it is determined whether or not the AC charging has been performed. Here, when it is determined that the charging is the AC charging, the process proceeds to step S22, and the charging control according to the charging voltage is performed as shown in FIG.

Next, in step S23, it is determined whether or not the charging is completed. Here, if the termination is determined, the process proceeds to step S25, and RA (not shown) in the CPU 11 is used.
A specific flag bit (end determination flag) in the M area is set to “1”. Further, in order to measure the time from this time, t = 0 is set in step S26.

On the other hand, if the camera is removed from the AC charger before the termination is determined in step S23, the process proceeds to step S24 and the termination determination flag is set to "0".
Is set to

If the end determination flag is "1", the process does not proceed to step S34 even if the process proceeds from step S27 to step S30, which will be described later, but proceeds to step S3.
At 5, the control to prohibit charging by the solar cell is performed.

However, when the end determination flag is "0", if the temperature range is OK in step S34, charging by the solar cell is permitted. When the temperature is measured by the CPU 11 and the temperature range is not appropriate, charging by the solar cell is prohibited in step S35.

When the release switch is turned on, the flow proceeds from step S27 to step S28, the photographing control is performed, and the end determination flag is cleared to "0" because current consumption has occurred and the battery is no longer in a fully charged state.

If it is determined in step S21 that the charging is not the AC charging, the flow shifts to step S27 to determine whether a release switch (not shown) is turned on. Here, if the release switch is turned on, step S
The flow shifts to 28, where shooting control is performed. Next, "0" is set to the end determination flag in step S29.

On the other hand, if the release switch has not been turned on in step S27, the flow shifts to step S30, where the time t is counted. Then, at step S31, whether or not a predetermined time t ₀ has elapsed. Here, when the time t ₀ elapses, step S3
In step 2, the flag is cleared to "0".

This is because the internal discharge of the battery is taken into account. Since the secondary battery is larger than the primary battery,
Even if there is no current consumption, a voltage drop can occur from a fully charged state over time. Therefore, when this flag becomes "0", charging by the solar cell is permitted in step S36 described later.

Then, in step S33, it is determined whether or not the end determination flag is "1". here,
If the end determination flag has been set to 1, the process proceeds to step S35, where control of charging inhibition by the solar cell is performed. Specifically, the transistor 24 of FIG. 1 is turned on, and the current is discarded to the ground.

On the other hand, if the end determination flag is "0" in step S33, the temperature range is determined in subsequent step S34. If the temperature range is OK in step S34, the process proceeds to step S36 and charging by the solar cell is permitted. Then, the above step S2
Move to 3.

On the other hand, if the temperature range is not appropriate in step S34, the flow shifts to step S35, where charging by the solar cell is prohibited.

As described above, according to the second embodiment, when the battery is fully charged by AC charging, charging by the solar cell is prohibited, so that overcharging can be prevented to extend the life of the battery. it can.

[0064]

As described above, according to the present invention, a rechargeable battery can be used many times and can be used without deterioration even if charged and discharged many times. Without doing so, it can be made a product that can be used for a long time.
This makes it possible to provide a camera that does not require battery replacement.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a camera and a charger of the camera according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of a camera and a charger of the camera according to the first embodiment of the present invention.

3A and 3B are diagrams illustrating a charging operation of a battery, in which FIG. 3A is a graph illustrating charging control of a lithium ion battery, and FIG. 3B is a diagram illustrating a relationship between a charging current and a temperature range.

FIG. 4 is a diagram showing an example when a warning is issued from a camera.

FIG. 5 is a flowchart illustrating an operation of the camera according to the first embodiment.

FIG. 6 is a flowchart illustrating Dotsu of a camera according to a second embodiment of the present invention.

FIG. 7 is a diagram for explaining the amount of energy charged in the battery and showing the relationship between the voltage and the amount of charge.

[Explanation of symbols]

 Reference Signs List 1 camera, 2 solar cell, 3 barrier, 4 strobe light emitting unit, 5 PCV, 6 display unit, 8 charger, 9 AC code, 10 user, 11 CPU, 12 DC / DC converter, 13 diode, 14 A / D converter , 15 reset IC, 16 display circuit, 17 warning section, 18 strobe, 19 temperature sensor, 20 EEPROM, 25 secondary battery, 30 AC / AC converter, 31 primary coil, 32 secondary coil, 33 rectifier circuit, 34 Stabilizing capacitor, 40 AC power supply.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H002 BB05 BC01 BC02 BC03 BC04 BC06 BC07 BC10 BC11 HA16 2H020 MA01 MA05 MC51 MC53 MC55 MC58 MC59 2H100 DD02 DD07 DD12 DD13 DD15 5F051 BA05 JA02 JA17 KA03 5G003 AA01 AA06 BA04 CB02 CC08 DA08 GB03 GC05

Claims (3)

[Claims] 1. A camera comprising: a solar cell; a secondary battery that accumulates an output current of the solar cell; and an electronic circuit that performs sequence control of the camera using the secondary battery as an energy source. The electronic circuit is obtained by first monitoring means for monitoring the charging voltage of the secondary battery, second monitoring means for monitoring the amount of charge to the solar cell, and the first and second monitoring means. Control means for controlling current consumption of the electronic circuit based on a charging voltage to the secondary battery and an amount of charge to the solar battery. 2. A camera comprising: a solar cell; a secondary battery that accumulates an output current of the solar cell; and an electronic circuit that performs sequence control of the camera using the secondary battery as an energy source. An electronic circuit comprising: a temperature detection unit that detects a temperature inside the camera; and a prohibition unit that prohibits a charging operation of the secondary battery according to an output result of the temperature detection unit. 3. In a camera using a secondary battery having two charging methods, a judging means for judging that charging by one charging method is completed, and judging a battery consumption after the judgment of the completion of charging. A camera comprising: a determination unit; and a permission unit that permits charging by another charging method according to a determination result of the determination unit.